Fault-tolerant power distribution with power source selection in a vehicle

ABSTRACT

A vehicle is provided that includes a basic structure; and coupled to the basic structure, a plurality of power sources, a propulsion system and power distribution circuitry. The propulsion system includes a plurality of electric motors configured to power a plurality of propulsors to generate propulsive forces that cause the vehicle to move. The power distribution circuitry is configured to deliver direct current electric power from the plurality of power sources to the plurality of electric motors. The power distribution circuitry electrically couples the plurality of power sources to the plurality of electric motors in an interleaved topology in which electric motors of the plurality of electric motors are alternately, electrically coupled to power sources of the plurality of power sources. Each of the electric motors in the interleaved topology is electrically coupled to a different one of the power sources than immediately adjacent ones of the electric motors.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. Provisional Application No.63/147,540, filed Feb. 9, 2021, entitled FAULT-TOLERANT POWERDISTRIBUTION WITH POWER SOURCE SELECTION INA VEHICLE, the content ofwhich is incorporated herein by reference in its entirety.

TECHNOLOGICAL FIELD

The present disclosure relates generally to electric power distributionand, in particular, to electric power distribution inelectrically-powered systems such as those onboard vehicles.

BACKGROUND

Electric and hybrid vehicles such as aerial vehicles, road vehicles andthe like are powered by sources of electric power such as batteries.These vehicles generally include one or more power sources, and apropulsion system one or more electric motors configured to power one ormore propulsors to generate propulsive forces that cause the vehicle tomove. Depending on the vehicle, these propulsors may include rotors,propellers, wheels and the like. The propulsion system may also includea drivetrain configured to deliver power from the electric motors to thepropulsors; and for some vehicles, the electric motors and drivetrainmay in some contexts be referred to as the powertrain of the vehicle.

In many of these vehicles, electric power from the power sources isdistributed to the electric motors via a centralized electric powerdistribution box designed to facilitate electric source switchover andback up in cases of certain failure modes. Existing power distributiondesigns usually have multiple channels of power sources, withcentralized monitoring and a control unit to detect failures and controlconnections between sources and loads. Some design instances useadditional channel via a dissimilar apparatus, and this channel isdesigned to have higher reliability for certain equipment such asnavigation equipment in the case of air vehicles.

BRIEF SUMMARY

As explained above, existing power distribution designs in electric andhybrid vehicles have provided back-up or failure isolation with acentralized electric power distribution box. New propulsionarchitectures in vehicles that use distributed propulsors driven byindividual electric motors at the propulsors has provided opportunity tosimplify the centralized electric power distribution box withself-arbitration between the available power sources, and improved backup and failure isolation coverage as well as propulsion systemreliability.

Example implementations of the present disclosure are directed toelectric power distribution and, in particular, to electric powerdistribution in electrically-powered systems such as those onboardvehicles. A vehicle according to some example implementations includes aplurality of power sources, and a propulsion system including aplurality of electric motors configured to power a plurality ofpropulsors. The vehicle also includes power distribution circuitry thatelectrically couples the plurality of power sources to the plurality ofelectric motors, such as in an interleaved topology in which electricmotors of the plurality of electric motors are alternately, electricallycoupled to power sources of the plurality of power sources. Exampleimplementations employ self-control fault tolerance that selects betweenpower sources based on their condition as operating normally or having afault or failure.

The present disclosure thus includes, without limitation, the followingexample implementations.

Some example implementations provide a vehicle comprising: a basicstructure; and coupled to the basic structure, a plurality of powersources; a propulsion system including a plurality of electric motorsconfigured to power a plurality of propulsors to generate propulsiveforces that cause the vehicle to move; and power distribution circuitryconfigured to deliver direct current (DC) electric power from theplurality of power sources to the plurality of electric motors, thepower distribution circuitry electrically coupling the plurality ofpower sources to the plurality of electric motors in an interleavedtopology in which electric motors of the plurality of electric motorsare alternately, electrically coupled to power sources of the pluralityof power sources, each of the electric motors electrically coupled to adifferent one of the power sources than immediately adjacent ones of theelectric motors.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the plurality of propulsors include one or more ofrotors, propellers or wheels.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, each of the electric motors is electrically coupled toa different one of the power sources than the immediately adjacent onesof the electric motors in either or both direction of a pitch axis or aroll axis of the vehicle.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the basic structure includes an airframe with afuselage and one or more pairs of wings that extend from opposing sidesof the fuselage, the plurality of electric motors are mounted to the oneor more pairs of wings, and each wing has multiple ones of the electricmotors mounted to the wing.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the multiple ones of the electric motors include atleast a first electric motor and a second electric motor electricallycoupled to respectively a first and a second of the power sources.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes: a pluralityof electric power buses electrically coupling the plurality of powersources to groups of the plurality of electric motors; a plurality ofswitches electrically coupled to and between the plurality of powersources and the plurality of electric power buses, the plurality ofswitches closed during normal operation of the plurality of powersources; one or more bus tie switches electrically coupled to andbetween power buses of the plurality of power sources, the one or morebus tie switches open during normal operation of the plurality of powersources; and power control circuitry configured to open one of theplurality of switches to disconnect a first of the plurality of powersources from a first of the plurality of electric power buses, and closeone of the one or more bus tie switches to connect the first of theplurality of electric power buses to a second of the plurality ofelectric power buses, automatically in direct response to a fault orfailure at the first of the plurality of power sources.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the first of the plurality of electric power buses andthe second of the plurality of electric power buses electrically couplesthe first of the plurality of power sources and a second of theplurality of power sources to respectively first and second groups ofthe plurality of electric motors, and wherein the power controlcircuitry is configured to open the one of the plurality of switches andclose the one of the one or more bus tie switches to electrically couplethe second of the plurality of power sources to the first and secondgroups of the plurality of electric motors.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes: a pluralityof electric power buses electrically coupling the plurality of powersources to the plurality of electric motors; and a plurality ofsource-selection circuitries that are separate and independent, andelectrically coupled to and between the plurality of electric powerbuses and the plurality of electric motors, and wherein a group of theplurality of source-selection circuitries is configured to switchablyconnect a first of the plurality of electric power buses and thereby afirst of the plurality of power sources to a first group of theplurality of electric motors during normal operation of the first of theplurality of power sources, and a second of the plurality of electricpower buses and thereby a second of the plurality of power sources tothe first group of the plurality of electric motors automatically indirect response to a fault or failure at the first of the plurality ofpower sources.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, a second group of the plurality of source-selectioncircuitries is configured to switchably connect the second of theplurality of electric power buses to a second group of the plurality ofelectric motors during normal operation of the second of the pluralityof power sources, and the first of the plurality of electric power busesto the second group of the plurality of electric motors automatically indirect response to the fault or failure at the second of the pluralityof power sources.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes: a pluralityof electric power buses electrically coupling the plurality of powersources to the plurality of electric motors; a plurality ofsource-selection circuitries that are separate and independent, andelectrically coupled to and between the plurality of power sources andthe plurality of electric power buses, and wherein a source-selectioncircuitry of the plurality of source-selection circuitries is configuredto switchably connect a first of the plurality of power sources to afirst of the plurality of electric power buses during normal operationof the first of the plurality of power sources, and a second of theplurality of power sources to the first of the plurality of electricpower buses automatically in direct response to a fault or failure atthe first of the plurality of power sources.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, a second source-selection circuitry of the plurality ofsource-selection circuitries is configured to switchably connect thesecond of the plurality of power sources to the second of the pluralityof electric power buses during normal operation of the second of theplurality of power sources, and the first of the plurality of powersources to the second of the plurality of electric power busesautomatically in direct response to the fault or failure at the secondof the plurality of power sources.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes: a pluralityof electric power buses with a plurality of feeders electricallycoupling the plurality of power sources to the plurality of electricmotors; and a plurality of interlocks electrically coupled to andbetween the plurality of feeders across the plurality of electric powerbuses, including interlocks configured to electrically couple feeders ofa first of the plurality of electric power buses to different feeders ofdifferent ones of others of the plurality of electric power buses,automatically and in direct response to a fault or failure at a first ofthe plurality of power sources electrically coupled to the first of theplurality of electric power buses.

In some example implementations of the vehicle of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the interlocks include switches that are open duringnormal operation of the plurality of power sources, and the interlocksare configured to close a first of the switches to connect a firstfeeder of the first of the plurality of electric power buses and one ofthe feeders of a second of the plurality of electric power buses, andclose a second of the switches to connect a second feeder of the firstof the plurality of electric power buses and one of the feeders of athird of the plurality of electric power buses.

Some example implementations provide a method of managing power in avehicle, the method comprising: providing the vehicle including aplurality of power sources, a propulsion system including a plurality ofelectric motors configured to power a plurality of propulsors togenerate propulsive forces that cause the vehicle to move, and powerdistribution circuitry; and delivering direct current (DC) electricpower from the plurality of power sources to the plurality of electricmotors via the power distribution circuitry electrically coupling theplurality of power sources to the plurality of electric motors in aninterleaved topology in which electric motors of the plurality ofelectric motors are alternately, electrically coupled to power sourcesof the plurality of power sources, each of the electric motorselectrically coupled to a different one of the power sources thanimmediately adjacent ones of the electric motors.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, delivering the DC electric power includes deliveringthe DC electric power via the power distribution circuitry in which eachof the electric motors is electrically coupled to a different one of thepower sources than the immediately adjacent ones of the electric motorsin either or both direction of a pitch axis or a roll axis of thevehicle.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, providing the vehicle includes providing the vehiclefurther including an airframe with a fuselage and one or more pairs ofwings that extend from opposing sides of the fuselage, the plurality ofelectric motors are mounted to the one or more pairs of wings, and eachwing has multiple ones of the electric motors mounted to the wing.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, delivering the DC electric power includes deliveringthe DC electric power via the power distribution circuitry in which themultiple ones of the electric motors include at least a first electricmotor and a second electric motor electrically coupled to respectively afirst and a second of the power sources.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes a pluralityof electric power buses electrically coupling the plurality of powersources to groups of the plurality of electric motors, a plurality ofswitches electrically coupled to and between the plurality of powersources and the plurality of electric power buses, and one or more bustie switches electrically coupled to and between power buses of theplurality of power sources, the plurality of switches and the one ormore bus tie switches respectively closed and open during normaloperation of the plurality of power sources, and wherein the methodfurther comprises opening one of the plurality of switches to disconnecta first of the plurality of power sources from a first of the pluralityof electric power buses, and closing one of the one or more bus tieswitches to connect the first of the plurality of electric power busesto a second of the plurality of electric power buses, automatically indirect response to a fault or failure at the first of the plurality ofpower sources.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the first of the plurality of electric power buses andthe second of the plurality of electric power buses electrically couplesthe first of the plurality of power sources and a second of theplurality of power sources to respectively first and second groups ofthe plurality of electric motors, and wherein the one of the pluralityof switches is opened, and the one of the one or more bus tie switchesis closed, to electrically couple the second of the plurality of powersources to the first and second groups of the plurality of electricmotors.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes a pluralityof electric power buses electrically coupling the plurality of powersources to the plurality of electric motors, and a plurality ofsource-selection circuitries that are separate and independent, andelectrically coupled to and between the plurality of electric powerbuses and the plurality of electric motors, and wherein the methodfurther comprises a group of the plurality of source-selectioncircuitries switchably connecting a first of the plurality of electricpower buses and thereby a first of the plurality of power sources to afirst group of the plurality of electric motors during normal operationof the first of the plurality of power sources, and a second of theplurality of electric power buses and thereby a second of the pluralityof power sources to the first group of the plurality of electric motorsautomatically in direct response to a fault or failure at the first ofthe plurality of power sources.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the method further comprises a second group of theplurality of source-selection circuitries switchably connecting thesecond of the plurality of electric power buses to a second group of theplurality of electric motors during normal operation of the second ofthe plurality of power sources, and the first of the plurality ofelectric power buses to the second group of the plurality of electricmotors automatically in direct response to the fault or failure at thesecond of the plurality of power sources.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes a pluralityof electric power buses electrically coupling the plurality of powersources to the plurality of electric motors, and a plurality ofsource-selection circuitries that are separate and independent, andelectrically coupled to and between the plurality of power sources andthe plurality of electric power buses, and wherein the method furthercomprises a source-selection circuitry of the plurality ofsource-selection circuitries switchably connecting a first of theplurality of power sources to a first of the plurality of electric powerbuses during normal operation of the first of the plurality of powersources, and a second of the plurality of power sources to the first ofthe plurality of electric power buses automatically in direct responseto a fault or failure at the first of the plurality of power sources.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the method further comprises a second source-selectioncircuitry of the plurality of source-selection circuitries switchablyconnecting the second of the plurality of power sources to the second ofthe plurality of electric power buses during normal operation of thesecond of the plurality of power sources, and the first of the pluralityof power sources to the second of the plurality of electric power busesautomatically in direct response to the fault or failure at the secondof the plurality of power sources.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the power distribution circuitry includes a pluralityof electric power buses with a plurality of feeders electricallycoupling the plurality of power sources to the plurality of electricmotors, and a plurality of interlocks electrically coupled to andbetween the plurality of feeders across the plurality of electric powerbuses, and wherein the method further comprises interlocks of theplurality of interlocks electrically coupling feeders of a first of theplurality of electric power buses to different feeders of different onesof others of the plurality of electric power buses, automatically and indirect response to a fault or failure at a first of the plurality ofpower sources electrically coupled to the first of the plurality ofelectric power buses.

In some example implementations of the method of any preceding exampleimplementation, or any combination of any preceding exampleimplementations, the interlocks include switches that are open duringnormal operation of the plurality of power sources, and wherein theinterlocks electrically coupling the feeders includes the interlocksclosing a first of the switches to connect a first feeder of the firstof the plurality of electric power buses and one of the feeders of asecond of the plurality of electric power buses, and closing a second ofthe switches to connect a second feeder of the first of the plurality ofelectric power buses and one of the feeders of a third of the pluralityof electric power buses.

These and other features, aspects, and advantages of the presentdisclosure will be apparent from a reading of the following detaileddescription together with the accompanying figures, which are brieflydescribed below. The present disclosure includes any combination of two,three, four or more features or elements set forth in this disclosure,regardless of whether such features or elements are expressly combinedor otherwise recited in a specific example implementation describedherein. This disclosure is intended to be read holistically such thatany separable features or elements of the disclosure, in any of itsaspects and example implementations, should be viewed as combinableunless the context of the disclosure clearly dictates otherwise.

It will therefore be appreciated that this Brief Summary is providedmerely for purposes of summarizing some example implementations so as toprovide a basic understanding of some aspects of the disclosure.Accordingly, it will be appreciated that the above described exampleimplementations are merely examples and should not be construed tonarrow the scope or spirit of the disclosure in any way. Other exampleimplementations, aspects and advantages will become apparent from thefollowing detailed description taken in conjunction with theaccompanying figures which illustrate, by way of example, the principlesof some described example implementations.

BRIEF DESCRIPTION OF THE FIGURE(S)

Having thus described example implementations of the disclosure ingeneral terms, reference will now be made to the accompanying figures,which are not necessarily drawn to scale, and wherein:

FIGS. 1A and 1B illustrate one type of vehicle, namely, an aircraft,according to example implementations of the present disclosure;

FIGS. 2, 3, 4 and 5 illustrate power distribution circuitry, accordingto various example implementations; and

FIGS. 6A, 6B, 6C, 6D, 6E, 6F and 6G are flowcharts illustrating varioussteps in a method of managing power in a vehicle, according to variousexample implementations.

DETAILED DESCRIPTION

Some implementations of the present disclosure will now be describedmore fully hereinafter with reference to the accompanying figures, inwhich some, but not all implementations of the disclosure are shown.Indeed, various implementations of the disclosure may be embodied inmany different forms and should not be construed as limited to theimplementations set forth herein; rather, these example implementationsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the disclosure to those skilled in theart. Like reference numerals refer to like elements throughout.

Unless specified otherwise or clear from context, references to first,second or the like should not be construed to imply a particular order.A feature described as being above another feature (unless specifiedotherwise or clear from context) may instead be below, and vice versa;and similarly, features described as being to the left of anotherfeature else may instead be to the right, and vice versa. Also, whilereference may be made herein to quantitative measures, values, geometricrelationships or the like, unless otherwise stated, any one or more ifnot all of these may be absolute or approximate to account foracceptable variations that may occur, such as those due to engineeringtolerances or the like.

As used herein, unless specified otherwise or clear from context, the“or” of a set of operands is the “inclusive or” and thereby true if andonly if one or more of the operands is true, as opposed to the“exclusive or” which is false when all of the operands are true. Thus,for example, “[A] or [B]” is true if [A] is true, or if [B] is true, orif both [A] and [B] are true. Further, the articles “a” and “an” mean“one or more,” unless specified otherwise or clear from context to bedirected to a singular form. Furthermore, it should be understood thatunless otherwise specified, the terms “data,” “content,” “digitalcontent,” “information,” and similar terms may be at times usedinterchangeably.

Example implementations of the present disclosure relate generally toelectric power distribution and, in particular, to electric powerdistribution in electrically-powered systems such as those onboardvehicles. As used herein, a vehicle is a machine designed as aninstrument of conveyance by land, water or air. A vehicle designed andconfigurable to fly may at times be referred to as an aerial vehicle oraircraft. A vehicle designed and configurable to operate with at leastsome level of autonomy may at times be referred to as an autonomousvehicle, or an autonomous aerial vehicle or aircraft in the case of anautonomous vehicle that is also designed and configurable to fly. Otherexamples of suitable vehicles include a variety of road vehicles, railedvehicles, watercraft (surface vessels, underwater vessels), amphibiousvehicles, spacecraft and the like. In some examples, the vehicle is anelectric vehicle such as an electric road or rail vehicle, an electricaircraft, an electric spacecraft or the like.

The vehicle may be manned or unmanned. The vehicle may be fullyhuman-controlled, or the vehicle may be semi-autonomous or autonomous inwhich at least some of its maneuvers are executed independent of or withminimal human intervention. In some examples, the vehicle is operable invarious modes with various amounts of human control.

A vehicle generally includes a basic structure; and coupled to the basicstructure, a power source, power distribution circuitry and a propulsionsystem. The basic structure is the main supporting structure of thevehicle to which other components are attached. The basic structure isthe load-bearing framework of the vehicle that structurally supports thevehicle in its construction and function. In various contexts, the basicstructure may be referred to as a chassis, an airframe or the like.

The power source is a source of power such as electric power from whichthe vehicle is powered to move; and in some examples, the vehicleincludes multiple or a plurality of power sources. Examples of suitablepower sources include batteries, solar panels, fuel cells, electricgenerators and the like. The power distribution circuitry includes powertransmission lines, power electronics and other circuitry fordistribution of power from the power source to an electrical load suchas the propulsion system and other onboard electronics.

The propulsion system includes one or more electric motors configured topower one or more propulsors to generate propulsive forces that causethe vehicle to move. Although not separately shown, in some examples,one or more motor controllers may be included to coordinate performanceof the one or more electric motors. A propulsor is any of a number ofdifferent means of converting power into a propulsive force. Examples ofsuitable propulsors include rotors, propellers, wheels and the like. Insome examples, the propulsion system includes a drivetrain configured todeliver power from the electric motors to the propulsors. The electricmotors and drivetrain may in some contexts be referred to as thepowertrain of the vehicle.

The vehicle may also include any of a number of other systems,subsystems, components and the like. In particular, for example, thevehicle may include a vehicle management system (VMS). The VMS is avehicle-specific subsystem configured to manage subsystems and othercomponents of the vehicle. These subsystems and other componentsinclude, for example, maneuver controls, landing gear, onboardenvironmental systems, electrical, pneumatic and hydraulic systems,communications systems, navigation systems and other subsystems andcomponents for controlling operation and maneuvering of the vehicle. TheVMS is configured to accept maneuver commands such as waypoints and/orsteering commands, and control the vehicle to follow those maneuvercommands.

FIGS. 1A and 1B illustrate one type of vehicle 100, namely, an aircraft,that may benefit from example implementations of the present disclosure.As shown, the vehicle generally includes a basic structure 102 with anairframe 104 with including a fuselage 106, and one or more pairs ofwings 108 that extend from opposing sides of the fuselage. The airframealso includes an empennage or tail assembly 110 at a rear end of thefuselage, and the tail assembly includes a stabilizer 112.

The vehicle 100 includes a plurality of power sources 114, and apropulsion system 116 including a plurality of electric motors 118configured to power a plurality of propulsors 120 to generate propulsiveforces that cause the vehicle to move. The vehicle as shown includestwelve electric motors (labeled M1-M12), and the propulsors are rotors.Depending on the vehicle, in various examples, the propulsors includeone or more of rotors, propellers or wheels. Also in the vehicle asshown, the plurality of electric motors are mounted to the one or morepairs of wings 108, and each wing has multiple ones of the electricmotors mounted to the wing. As also shown, power distribution circuitry122 electrically couples the plurality of power sources to the pluralityof electric motors. The power distribution circuitry is configured todeliver electric power from the plurality of power sources to theplurality of electric motors.

As shown more particularly in FIG. 1B, according to some exampleimplementations of the present disclosure, the power distributioncircuitry 122 electrically couples the plurality of power sources 114 tothe plurality of electric motors 118 in an interleaved topology. In someexamples of this topology, electric motors of the plurality of electricmotors are alternately, electrically coupled to power sources of theplurality of power sources. Each of the electric motors is electricallycoupled to a different one of the power sources than immediatelyadjacent ones of the electric motors. In some examples, each of theelectric motors is electrically coupled to a different one of the powersources than the immediately adjacent ones of the electric motors ineither or both direction of a pitch axis or a roll axis of the vehicle.

The interleaved topology in which the power distribution circuitry 122electrically couples the plurality of power sources 114 to the pluralityof electric motors 118 may be implemented in a number of differentmanners depending on the need or role of the electric motors. In thevehicle 100 as shown, the first row of propulsors 120 are tiltedrelative to the other rows of propulsors. The first row of propulsors isprimarily responsible for transition and forward flight (i.e., forwardthrust). Higher redundancy may be required for the first row ofpropulsors relative to the other rows of propulsors. In otherconfigurations, the electrical coupling may be distributed in adifferent manner or level.

In some examples in which the vehicle 100 is an aircraft, the pluralityof electric motors 118 are mounted to the one or more pairs of wings108, and each wing has multiple ones of the electric motors mounted tothe wing. In some of these examples, the multiple ones of the electricmotors include at least a first electric motor and a second electricmotor electrically coupled to respectively a first and a second of thepower sources 114A, 114B. As shown, in particular, the multiple ones ofthe electric motors may include first electric motors M1, M3, M6, M8,M9, M11, and second electric motors M2, M4, M5, M7, M10, M12electrically coupled to respectively the first and the second of thepower sources.

FIGS. 2, 3, 4 and 5 illustrate power distribution circuitry that invarious example implementations may correspond to the power distributioncircuitry 122 shown in FIGS. 1A and 1B. The power distribution circuitryis shown and described herein in the context of a vehicle including anumber of power sources, electric motors and propulsors. The numbers ofthese and other components shown in the figures are provided by way ofexample and should not be taken as limiting. The power distributioncircuitry according to the various example implementations mayelectrically couple any number of power sources to any number ofelectric motors, according to example implementations of the presentdisclosure.

FIG. 2 illustrates power distribution circuitry 200 according to someexample implementations. As shown, the power distribution circuitry 200includes a plurality of electric power buses 202 electrically couplingthe plurality of power sources 114 to groups 204 of the plurality ofelectric motors 118. The power distribution circuitry includes aplurality of switches 206 electrically coupled to and between theplurality of power sources and the plurality of electric power buses,and one or more bus tie switches 208 electrically coupled to and betweenpower buses of the plurality of power sources. The plurality of switchesare closed during normal operation of the plurality of power sources,and the one or more bus tie switches are open during normal operation ofthe plurality of power sources.

As also shown, the power distribution circuitry includes power controlcircuitry 210 configured to control the plurality of switches 206 andthe one or more bus tie switches 208 based on conditions of theplurality of power sources 114. Although not separately shown, the powercontrol circuitry may include bus sensing circuitry, which may beimplemented in a number of different manners. The bus sensing circuitrymay be implemented using relays to sense input states of the pluralityof power sources, and control the plurality of switches and the one ormore bus tie switches. Other examples include sensing the input statesof the plurality of power sources with voltage transducers, controllingthe plurality of switches and the one or more bus tie switches withsolid-state switches, and the like.

According to some example implementations, the power control circuitry210 is configured to open one of the plurality of switches 206 todisconnect a first of the plurality of power sources 114A from a firstof the plurality of electric power buses 202A, and close one of the oneor more bus tie switches 208 to connect the first of the plurality ofelectric power buses to a second of the plurality of electric powerbuses 202B. In this regard, the power control circuitry is configured toopen and close the respective switches, automatically in direct responseto a fault or failure at the first of the plurality of power sources.

In some further examples, the first of the plurality of electric powerbuses 202A and the second of the plurality of electric power buses 202Belectrically couple the first of the plurality of power sources 114A anda second of the plurality of power sources 114B to respectively firstand second groups 204A, 204B of the plurality of electric motors 118. Insome of these examples, the power control circuitry 210 is configured toopen the one of the plurality of switches 206 and close the one of theone or more bus tie switches 208 to electrically couple the second ofthe plurality of power sources to the first and second groups of theplurality of electric motors.

FIG. 3 illustrates power distribution circuitry 300 according to otherexample implementations. As shown, the power distribution circuitry 300includes a plurality of electric power buses 302 electrically couplingthe plurality of power sources 114 to the plurality of electric motors118. The power distribution circuitry includes a plurality ofsource-selection circuitries 304 that are separate and independent, andelectrically coupled to and between the plurality of electric powerbuses and the plurality of electric motors.

According to some implementations, a group 306A of the plurality ofsource-selection circuitries 304 is configured to switchably connect afirst or a second of the plurality of electric power buses 302A, 302B,and thereby a first or a second of the plurality of power sources 114A,114B, to a first group 308A of the plurality of electric motors 118based on conditions of the plurality of power sources 114. In thisregard, in some examples, the plurality of source-selection circuitriesis configured to connect the first of the plurality of electric powerbuses, and thereby the first of the plurality of power sources, to thefirst group of the plurality of electric motors during normal operationof the first of the plurality of power sources. The plurality ofsource-selection circuitries is configured to connect the second of theplurality of electric power buses, and thereby the second of theplurality of power sources, to the first group of the plurality ofelectric motors automatically in direct response to a fault or failureat the first of the plurality of power sources.

In some further examples, a second group 306B of the plurality ofsource-selection circuitries 304 is configured to switchably connect thefirst or the second of the plurality of electric power buses 302A, 302B,and thereby the first or a second of the plurality of power sources114A, 114B, to a second group 308B of the plurality of electric motors118 based on conditions of the plurality of power sources 114. Thesecond group of the plurality of source-selection circuitries isconfigured to connect the second of the plurality of electric powerbuses to the second group of the plurality of electric motors duringnormal operation of the second of the plurality of power sources. Thesecond group of the plurality of source-selection circuitries isconfigured to connect the first of the plurality of electric power busesto the second group of the plurality of electric motors automatically indirect response to the fault or failure at the second of the pluralityof power sources.

FIG. 4 illustrates power distribution circuitry 400 according to yetother example implementations. As shown, the power distributioncircuitry 400 includes a plurality of electric power buses 402electrically coupling the plurality of power sources 114 to theplurality of electric motors 118. The power distribution circuitryincludes a plurality of source-selection circuitries 404 that areseparate and independent, and electrically coupled to and between theplurality of power sources and the plurality of electric power buses.

According to some of these examples, a source-selection circuitry 404Aof the plurality of source-selection circuitries 404 is configured toswitchably connect a first or a second of the plurality of power sources114A, 114B to a first of the plurality of electric power buses 402Abased on a condition of the first of the plurality of power sources. Thesource-selection circuitry is configured to connect the first of theplurality of power sources to the first of the plurality of electricpower buses during normal operation of the first of the plurality ofpower sources. The source-selection circuitry is configured to connectthe second of the plurality of power sources to the first of theplurality of electric power buses automatically in direct response to afault or failure at the first of the plurality of power sources.

In some further examples, a second source-selection circuitry 404B ofthe plurality of source-selection circuitries 404 is configured toswitchably connect a first or a second of the plurality of power sources114A, 114B to a second of the plurality of electric power buses 402Bbased on a condition of the second of the plurality of power sources.The second source-selection circuitry is configured to connect thesecond of the plurality of power sources to the second of the pluralityof electric power buses during normal operation of the second of theplurality of power sources. And the second source-selection circuitry isconfigured to connect the first of the plurality of power sources to thesecond of the plurality of electric power buses automatically in directresponse to the fault or failure at the second of the plurality of powersources.

FIG. 5 illustrates power distribution circuitry 500 according to someexample implementations. As shown, the power distribution circuitry 500includes a plurality of electric power buses 502 with a plurality offeeders 504 electrically coupling the plurality of power sources 114 tothe plurality of electric motors 118. The power distribution circuitryalso includes a plurality of interlocks 506 electrically coupled to andbetween the plurality of feeders across the plurality of electric powerbuses. This includes interlocks configured to electrically couplefeeders of a first of the plurality of electric power buses 502A todifferent feeders of different ones of others of the plurality ofelectric power buses 502B, 502C, automatically and in direct response toa fault or failure at a first of the plurality of power sources 114Aelectrically coupled to the first of the plurality of electric powerbuses.

In some further examples, the interlocks include switches 508 that areopen during normal operation of the plurality of power sources 114. Insome of these examples, the interlocks are configured to close a firstof the switches 508A to connect a first feeder 504A of the first of theplurality of electric power buses 502A and one of the feeders 504C of asecond of the plurality of electric power buses 502B. Likewise, theinterlocks are configured to close a second of the switches 508B toconnect a second feeder 504B of the first of the plurality of electricpower buses and one of the feeders 504D of a third of the plurality ofelectric power buses 502C.

FIGS. 6A-6G are flowcharts illustrating various steps in a method 600 ofmanaging power in a vehicle 100, according to various exampleimplementations. The method includes providing the vehicle including aplurality of power sources 114, a propulsion system 116 including aplurality of electric motors 118 configured to power a plurality ofpropulsors 120 to generate propulsive forces that cause the vehicle tomove, and power distribution circuitry 122, as shown at block 602 ofFIG. 6A. The method also includes delivering direct current DC electricpower from the plurality of power sources to the plurality of electricmotors via the power distribution circuitry electrically coupling theplurality of power sources to the plurality of electric motors in aninterleaved topology, as shown at block 604. Again, in this topology,which electric motors of the plurality of electric motors arealternately, electrically coupled to power sources of the plurality ofpower sources, each of the electric motors electrically coupled to adifferent one of the power sources than immediately adjacent ones of theelectric motors.

In some examples, delivering the DC electric power at block 604 includesdelivering the DC electric power via the power distribution circuitry122 in which each of the electric motors 118 is electrically coupled toa different one of the power sources 114 than the immediately adjacentones of the electric motors in either or both direction of a pitch axisor a roll axis of the vehicle 100.

In some examples, providing the vehicle 100 at block 602 includesproviding the vehicle further including an airframe 104 with a fuselage106 and one or more pairs of wings 108 that extend from opposing sidesof the fuselage. In some of these examples, the plurality of electricmotors 118 are mounted to the one or more pairs of wings, and each winghas multiple ones of the electric motors mounted to the wing.

In some examples, delivering the DC electric power at block 604 includesdelivering the DC electric power via the power distribution circuitry122 in which the multiple ones of the electric motors 118 include atleast a first electric motor (e.g., M1, M3, M6, M8, M9, M11) and asecond electric motor (e.g., M2, M4, M5, M7, M10, M12) electricallycoupled to respectively a first and a second of the power sources 114A,114B.

In some examples, the power distribution circuitry 122, 200 includes aplurality of electric power buses 202 electrically coupling theplurality of power sources 114 to groups 204 of the plurality ofelectric motors 118. The power distribution circuitry also includes aplurality of switches 206 electrically coupled to and between theplurality of power sources and the plurality of electric power buses,and one or more bus tie switches 208 electrically coupled to and betweenpower buses of the plurality of power sources. The plurality of switchesand the one or more bus tie switches respectively closed and open duringnormal operation of the plurality of power sources.

Also in some of these examples, the method 600 further includes openingone of the plurality of switches to disconnect a first of the pluralityof power sources 114A from a first of the plurality of electric powerbuses 202A, as shown at block 606 of FIG. 6B. The method also includesclosing one of the one or more bus tie switches to connect the first ofthe plurality of electric power buses to a second of the plurality ofelectric power buses 202B, automatically in direct response to a faultor failure at the first of the plurality of power sources, as shown atblock 608.

In some further examples, the first of the plurality of electric powerbuses 202A and the second of the plurality of electric power buses 202Belectrically couples the first of the plurality of power sources 114Aand a second of the plurality of power sources 114B to respectivelyfirst and second groups 204A, 204B of the plurality of electric motors118. In some of these examples, the one of the plurality of switches isopened at block 606, and the one of the one or more bus tie switches isclosed at block 608, to electrically couple the second of the pluralityof power sources to the first and second groups of the plurality ofelectric motors.

In some examples, the power distribution circuitry 122, 300 includes aplurality of electric power buses 302 electrically coupling theplurality of power sources 114 to the plurality of electric motors 118.The power distribution circuitry also includes a plurality ofsource-selection circuitries 304 that are separate and independent, andelectrically coupled to and between the plurality of electric powerbuses and the plurality of electric motors.

Also in some of these examples, the method 600 further includes a group306A of the plurality of source-selection circuitries switchablyconnecting a first or a second of the plurality of electric power buses302A, and thereby a first or a second of the plurality of power sources114A, to a first group 308A of the plurality of electric motors, asshown at blocks 610 and 612 of FIG. 6C. The group of the plurality ofsource-selection circuitries connect the first of the plurality ofelectric power buses (and thereby the first of the plurality of powersources) to the first group of the plurality of electric motors duringnormal operation of the first of the plurality of power sources. And thegroup of the plurality of source-selection circuitries connect thesecond of the plurality of electric power buses (and thereby the secondof the plurality of power sources) to the first group of the pluralityof electric motors automatically in direct response to a fault orfailure at the first of the plurality of power sources.

In some further examples, the method 600 further includes a second group306B of the plurality of source-selection circuitries switchablyconnecting the first or the second of the plurality of electric powerbuses 302A, and thereby the first or the second of the plurality ofpower sources 114A, to a first group 308A of the plurality of electricmotors, as shown at blocks 614 and 616 of FIG. 6D. The second group ofthe plurality of source-selection circuitries connect the second of theplurality of electric power buses (and thereby the second of theplurality of power sources) to the second group of the plurality ofelectric motors during normal operation of the second of the pluralityof power sources. And the second group of the plurality ofsource-selection circuitries connect the first of the plurality ofelectric power buses (and thereby the first of the plurality of powersources) to the second group of the plurality of electric motorsautomatically in direct response to a fault or failure at the second ofthe plurality of power sources.

In some examples, the power distribution circuitry 122, 400 includes aplurality of electric power buses 402 electrically coupling theplurality of power sources 114 to the plurality of electric motors 118.The power distribution circuitry also includes a plurality ofsource-selection circuitries 404 that are separate and independent, andelectrically coupled to and between the plurality of power sources andthe plurality of electric power buses.

The method 600 in some of these examples further includes asource-selection circuitry 404A of the plurality of source-selectioncircuitries 404 switchably connecting a first or a second of theplurality of power sources 114A, 114B to a first of the plurality ofelectric power buses 402A, as shown at blocks 618 and 620 of FIG. 6E.The source-selection circuitry connects the first of the plurality ofpower sources to the first of the plurality of electric power busesduring normal operation of the first of the plurality of power sources.And the source-selection circuitry connects the second of the pluralityof power sources to the first of the plurality of electric power busesautomatically in direct response to a fault or failure at the first ofthe plurality of power sources.

In some further examples, the method 600 further includes a secondsource-selection circuitry 404B of the plurality of source-selectioncircuitries 404 switchably connecting the first or the second of theplurality of power sources 114A, 114B to a second of the plurality ofelectric power buses 402B, as shown at blocks 622 and 624 of FIG. 6F.The second source-selection circuitry connects the second of theplurality of power sources to the second of the plurality of electricpower buses during normal operation of the second of the plurality ofpower sources. And the second source-selection circuitry connects thefirst of the plurality of power sources to the second of the pluralityof electric power buses automatically in direct response to a fault orfailure at the second of the plurality of power sources.

In some examples, the power distribution circuitry 122, 500 includes aplurality of electric power buses 502 with a plurality of feeders 504electrically coupling the plurality of power sources 114 to theplurality of electric motors 118, and a plurality of interlocks 506electrically coupled to and between the plurality of feeders across theplurality of electric power buses. In some of these examples, the method600 further includes interlocks of the plurality of interlockselectrically coupling feeders of a first of the plurality of electricpower buses 502A to different feeders of different ones of others of theplurality of electric power buses 502B, 502C, automatically and indirect response to a fault or failure at a first of the plurality ofpower sources 114A electrically coupled to the first of the plurality ofelectric power buses, as shown at block 626 of FIG. 6G

In some further examples, the interlocks include switches 508 that areopen during normal operation of the plurality of power sources 114. Insome of these examples, the interlocks electrically coupling the feedersat block 626 includes the interlocks closing a first of the switches508A to connect a first feeder 504A of the first of the plurality ofelectric power buses 502A and one of the feeders 504C of a second of theplurality of electric power buses 502B, as shown at block 628. Theinterlocks also close a second of the switches 508B to connect a secondfeeder 504B of the first of the plurality of electric power buses andone of the feeders 504D of a third of the plurality of electric powerbuses 502C, as shown at block 630.

Many modifications and other implementations of the disclosure set forthherein will come to mind to one skilled in the art to which thedisclosure pertains having the benefit of the teachings presented in theforegoing description and the associated figures. Therefore, it is to beunderstood that the disclosure is not to be limited to the specificimplementations disclosed and that modifications and otherimplementations are intended to be included within the scope of theappended claims. Moreover, although the foregoing description and theassociated figures describe example implementations in the context ofcertain example combinations of elements and/or functions, it should beappreciated that different combinations of elements and/or functions maybe provided by alternative implementations without departing from thescope of the appended claims. In this regard, for example, differentcombinations of elements and/or functions than those explicitlydescribed above are also contemplated as may be set forth in some of theappended claims. Although specific terms are employed herein, they areused in a generic and descriptive sense only and not for purposes oflimitation.

What is claimed is:
 1. A vehicle comprising: a basic structure; andcoupled to the basic structure, a plurality of power sources; apropulsion system including a plurality of electric motors configured topower a plurality of propulsors to generate propulsive forces that causethe vehicle to move; and power distribution circuitry configured todeliver direct current (DC) electric power from the plurality of powersources to the plurality of electric motors, the power distributioncircuitry electrically coupling the plurality of power sources to theplurality of electric motors in an interleaved topology in whichelectric motors of the plurality of electric motors are alternately,electrically coupled to power sources of the plurality of power sources,each of the electric motors electrically coupled to a different one ofthe power sources than immediately adjacent ones of the electric motors.2. The vehicle of claim 1, wherein the plurality of propulsors includeone or more of rotors, propellers or wheels.
 3. The vehicle of claim 1,wherein each of the electric motors is electrically coupled to adifferent one of the power sources than the immediately adjacent ones ofthe electric motors in either or both direction of a pitch axis or aroll axis of the vehicle.
 4. The vehicle of claim 1, wherein the basicstructure includes an airframe with a fuselage and one or more pairs ofwings that extend from opposing sides of the fuselage, the plurality ofelectric motors are mounted to the one or more pairs of wings, and eachwing has multiple ones of the electric motors mounted to the wing. 5.The vehicle of claim 4, wherein the multiple ones of the electric motorsinclude at least a first electric motor and a second electric motorelectrically coupled to respectively a first and a second of the powersources.
 6. The vehicle of claim 1, wherein the power distributioncircuitry includes: a plurality of electric power buses electricallycoupling the plurality of power sources to groups of the plurality ofelectric motors; a plurality of switches electrically coupled to andbetween the plurality of power sources and the plurality of electricpower buses, the plurality of switches closed during normal operation ofthe plurality of power sources; one or more bus tie switcheselectrically coupled to and between power buses of the plurality ofpower sources, the one or more bus tie switches open during normaloperation of the plurality of power sources; and power control circuitryconfigured to open one of the plurality of switches to disconnect afirst of the plurality of power sources from a first of the plurality ofelectric power buses, and close one of the one or more bus tie switchesto connect the first of the plurality of electric power buses to asecond of the plurality of electric power buses, automatically in directresponse to a fault or failure at the first of the plurality of powersources.
 7. The vehicle of claim 6, wherein the first of the pluralityof electric power buses and the second of the plurality of electricpower buses electrically couples the first of the plurality of powersources and a second of the plurality of power sources to respectivelyfirst and second groups of the plurality of electric motors, and whereinthe power control circuitry is configured to open the one of theplurality of switches and close the one of the one or more bus tieswitches to electrically couple the second of the plurality of powersources to the first and second groups of the plurality of electricmotors.
 8. The vehicle of claim 1, wherein the power distributioncircuitry includes: a plurality of electric power buses electricallycoupling the plurality of power sources to the plurality of electricmotors; and a plurality of source-selection circuitries that areseparate and independent, and electrically coupled to and between theplurality of electric power buses and the plurality of electric motors,and wherein a group of the plurality of source-selection circuitries isconfigured to switchably connect a first of the plurality of electricpower buses and thereby a first of the plurality of power sources to afirst group of the plurality of electric motors during normal operationof the first of the plurality of power sources, and a second of theplurality of electric power buses and thereby a second of the pluralityof power sources to the first group of the plurality of electric motorsautomatically in direct response to a fault or failure at the first ofthe plurality of power sources.
 9. The vehicle of claim 8, wherein asecond group of the plurality of source-selection circuitries isconfigured to switchably connect the second of the plurality of electricpower buses to a second group of the plurality of electric motors duringnormal operation of the second of the plurality of power sources, andthe first of the plurality of electric power buses to the second groupof the plurality of electric motors automatically in direct response tothe fault or failure at the second of the plurality of power sources.10. The vehicle of claim 1, wherein the power distribution circuitryincludes: a plurality of electric power buses electrically coupling theplurality of power sources to the plurality of electric motors; aplurality of source-selection circuitries that are separate andindependent, and electrically coupled to and between the plurality ofpower sources and the plurality of electric power buses, and wherein asource-selection circuitry of the plurality of source-selectioncircuitries is configured to switchably connect a first of the pluralityof power sources to a first of the plurality of electric power busesduring normal operation of the first of the plurality of power sources,and a second of the plurality of power sources to the first of theplurality of electric power buses automatically in direct response to afault or failure at the first of the plurality of power sources.
 11. Thevehicle of claim 10, wherein a second source-selection circuitry of theplurality of source-selection circuitries is configured to switchablyconnect the second of the plurality of power sources to the second ofthe plurality of electric power buses during normal operation of thesecond of the plurality of power sources, and the first of the pluralityof power sources to the second of the plurality of electric power busesautomatically in direct response to the fault or failure at the secondof the plurality of power sources.
 12. The vehicle of claim 1, whereinthe power distribution circuitry includes: a plurality of electric powerbuses with a plurality of feeders electrically coupling the plurality ofpower sources to the plurality of electric motors; and a plurality ofinterlocks electrically coupled to and between the plurality of feedersacross the plurality of electric power buses, including interlocksconfigured to electrically couple feeders of a first of the plurality ofelectric power buses to different feeders of different ones of others ofthe plurality of electric power buses, automatically and in directresponse to a fault or failure at a first of the plurality of powersources electrically coupled to the first of the plurality of electricpower buses.
 13. The vehicle of claim 12, wherein the interlocks includeswitches that are open during normal operation of the plurality of powersources, and the interlocks are configured to close a first of theswitches to connect a first feeder of the first of the plurality ofelectric power buses and one of the feeders of a second of the pluralityof electric power buses, and close a second of the switches to connect asecond feeder of the first of the plurality of electric power buses andone of the feeders of a third of the plurality of electric power buses.14. A method of managing power in a vehicle, the method comprising:providing the vehicle including a plurality of power sources, apropulsion system including a plurality of electric motors configured topower a plurality of propulsors to generate propulsive forces that causethe vehicle to move, and power distribution circuitry; and deliveringdirect current (DC) electric power from the plurality of power sourcesto the plurality of electric motors via the power distribution circuitryelectrically coupling the plurality of power sources to the plurality ofelectric motors in an interleaved topology in which electric motors ofthe plurality of electric motors are alternately, electrically coupledto power sources of the plurality of power sources, each of the electricmotors electrically coupled to a different one of the power sources thanimmediately adjacent ones of the electric motors.
 15. The method ofclaim 14, wherein delivering the DC electric power includes deliveringthe DC electric power via the power distribution circuitry in which eachof the electric motors is electrically coupled to a different one of thepower sources than the immediately adjacent ones of the electric motorsin either or both direction of a pitch axis or a roll axis of thevehicle.
 16. The method of claim 14, wherein providing the vehicleincludes providing the vehicle further including an airframe with afuselage and one or more pairs of wings that extend from opposing sidesof the fuselage, the plurality of electric motors are mounted to the oneor more pairs of wings, and each wing has multiple ones of the electricmotors mounted to the wing.
 17. The method of claim 16, whereindelivering the DC electric power includes delivering the DC electricpower via the power distribution circuitry in which the multiple ones ofthe electric motors include at least a first electric motor and a secondelectric motor electrically coupled to respectively a first and a secondof the power sources.
 18. The method of claim 14, wherein the powerdistribution circuitry includes a plurality of electric power buseselectrically coupling the plurality of power sources to groups of theplurality of electric motors, a plurality of switches electricallycoupled to and between the plurality of power sources and the pluralityof electric power buses, and one or more bus tie switches electricallycoupled to and between power buses of the plurality of power sources,the plurality of switches and the one or more bus tie switchesrespectively closed and open during normal operation of the plurality ofpower sources, and wherein the method further comprises opening one ofthe plurality of switches to disconnect a first of the plurality ofpower sources from a first of the plurality of electric power buses, andclosing one of the one or more bus tie switches to connect the first ofthe plurality of electric power buses to a second of the plurality ofelectric power buses, automatically in direct response to a fault orfailure at the first of the plurality of power sources.
 19. The methodof claim 18, wherein the first of the plurality of electric power busesand the second of the plurality of electric power buses electricallycouples the first of the plurality of power sources and a second of theplurality of power sources to respectively first and second groups ofthe plurality of electric motors, and wherein the one of the pluralityof switches is opened, and the one of the one or more bus tie switchesis closed, to electrically couple the second of the plurality of powersources to the first and second groups of the plurality of electricmotors.
 20. The method of claim 14, wherein the power distributioncircuitry includes a plurality of electric power buses electricallycoupling the plurality of power sources to the plurality of electricmotors, and a plurality of source-selection circuitries that areseparate and independent, and electrically coupled to and between theplurality of electric power buses and the plurality of electric motors,and wherein the method further comprises a group of the plurality ofsource-selection circuitries switchably connecting a first of theplurality of electric power buses and thereby a first of the pluralityof power sources to a first group of the plurality of electric motorsduring normal operation of the first of the plurality of power sources,and a second of the plurality of electric power buses and thereby asecond of the plurality of power sources to the first group of theplurality of electric motors automatically in direct response to a faultor failure at the first of the plurality of power sources.
 21. Themethod of claim 20, further comprising a second group of the pluralityof source-selection circuitries switchably connecting the second of theplurality of electric power buses to a second group of the plurality ofelectric motors during normal operation of the second of the pluralityof power sources, and the first of the plurality of electric power busesto the second group of the plurality of electric motors automatically indirect response to the fault or failure at the second of the pluralityof power sources.
 22. The method of claim 14, wherein the powerdistribution circuitry includes a plurality of electric power buseselectrically coupling the plurality of power sources to the plurality ofelectric motors, and a plurality of source-selection circuitries thatare separate and independent, and electrically coupled to and betweenthe plurality of power sources and the plurality of electric powerbuses, and wherein the method further comprises a source-selectioncircuitry of the plurality of source-selection circuitries switchablyconnecting a first of the plurality of power sources to a first of theplurality of electric power buses during normal operation of the firstof the plurality of power sources, and a second of the plurality ofpower sources to the first of the plurality of electric power busesautomatically in direct response to a fault or failure at the first ofthe plurality of power sources.
 23. The method of claim 22, furthercomprising a second source-selection circuitry of the plurality ofsource-selection circuitries switchably connecting the second of theplurality of power sources to the second of the plurality of electricpower buses during normal operation of the second of the plurality ofpower sources, and the first of the plurality of power sources to thesecond of the plurality of electric power buses automatically in directresponse to the fault or failure at the second of the plurality of powersources.
 24. The method of claim 14, wherein the power distributioncircuitry includes a plurality of electric power buses with a pluralityof feeders electrically coupling the plurality of power sources to theplurality of electric motors, and a plurality of interlocks electricallycoupled to and between the plurality of feeders across the plurality ofelectric power buses, and wherein the method further comprisesinterlocks of the plurality of interlocks electrically coupling feedersof a first of the plurality of electric power buses to different feedersof different ones of others of the plurality of electric power buses,automatically and in direct response to a fault or failure at a first ofthe plurality of power sources electrically coupled to the first of theplurality of electric power buses.
 25. The method of claim 24, whereinthe interlocks include switches that are open during normal operation ofthe plurality of power sources, and wherein the interlocks electricallycoupling the feeders includes the interlocks closing a first of theswitches to connect a first feeder of the first of the plurality ofelectric power buses and one of the feeders of a second of the pluralityof electric power buses, and closing a second of the switches to connecta second feeder of the first of the plurality of electric power busesand one of the feeders of a third of the plurality of electric powerbuses.